There have been a number of efforts addressing the tragic deaths of children who have been mistakenly left in automobiles or vehicles after the driver had reached his/her desired destination and left the vehicle. The deaths have usually been caused by a buildup of excessive heat or excessive cold within the vehicle during the absence of the driver. Conventional infant car seats and toddler booster seats are intended to restrain the infant or toddler during transportation within the vehicle, and are typically designed so that the infant or toddler cannot by oneself release the seat belt or restraint. Infants and small children are rapidly susceptible to hyperthermia when subjected to the elevated temperatures within an enclosed vehicle, with sometimes fatal consequences.
Review of child accidental deaths cases due to hyperthermia in vehicles demonstrates that this usually occurs when the parent or caretaker has deviated from a usual routine with the child. For example, a different vehicle is used, or a different parent takes the child to a destination that day due to the exigencies of family and work life.
The prior art includes numerous references that suggest detecting the status of a vehicle's ignition and determining the presence of a child in the child safety seat, to alert the driver that the child is still in the child safety seat when the drive is ended, including U.S. Pat. Publication Nos. 2009/0079557 and 2011/0109450, and U.S. Pat. Nos. 6,104,293, 5,949,340, and 6,489,889, the disclosures of which are incorporated by reference. However, none of these references describe in specific detail how a device or a method using the device detects or determines the vehicle ignition status or state, using information collected from a network on the vehicle. There is, for example, no known mandated network message that identifies the position of the vehicle key in the ignition as in either the ‘on’ or ‘off’ position.
Modern vehicles use onboard data networks to communicate useful information between microcontrollers found both within the vehicle and within devices attached to the OBD-II port. Microcontrollers communicating on the vehicle network “query” (request information from) other microcontrollers on the network by transmitting a request message containing a predefined Parameter Identifier (PID). One or more microcontrollers on the network respond to such a query by transmitting a response message containing the value of the requested vehicle operating parameter (for example, engine revolutions per minute (RPM) or vehicle speed).
U.S. law, and by law in other countries, mandates the reporting of standard parameters by the vehicle network when queried via a device connected to standard sockets (Pins 6 and 14, in the case of the CAN protocol) on the OBD-II port. ISO 15765 defines the Controller Area Network (CAN) protocol that is mandated for use in North American passenger and light truck vehicles since 2008. Reference is made to http://en.wikipedia.org/wiki/OBD-II_PIDs. The OBD-II port has been a required feature on all passenger vehicles and light trucks sold in the US since Jan. 1, 1996. These networks use CAN and other communication protocols.
US Patent Publ. No. 2014/0052342 (Seibert), the disclosure of which is incorporated by reference, discloses a portable device that plugs directly into the OBD-II port of a vehicle that queries a vehicle network through the OBD-II port for the value of a parameter(s), and generating an alarm in response to a predetermined condition of the parameter(s), and a buckle status signal from a child restraint device of a safety seat.
In view of the above, there remains a need to provide a convenient, more portable, effective system for use by drivers of vehicles for determining, or inferring with high predictability, the status of a driver's journey, indicating when the driver has ended the journey and has arrived at his/her desired destination, has turned off the operating systems of the vehicle, and will leave the vehicle. Such a convenient, portable and effective device or system could then be used in combination with a device that detects the presence of a child in a child safety seat or that detects the restraint status of the child in the child safety seat, so that an alarm can be generated that warns the driver when a child has been left secured into the child safety seat after the journey has ended.